Cloud seeding hopes to help fight drought by increasing rain

We visited one of the longest-running cloud-seeding operations in the country to get a demo of the technology behind real weather modification.

Jesse Orrall Senior Video Producer
Jesse Orrall (he/him/his) is a Senior Video Producer for CNET. He covers future tech, sustainability and the social impact of technology. He is co-host of CNET's "What The Future" series and Executive Producer of "Experts React." Aside from making videos, he's a certified SCUBA diver with a passion for music, films, history and ecology.
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Jesse Orrall
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California is in the midst of its third-driest year on record, Vice President Kamala Harris recently predicted that wars "will be fought over water," and water futures are now being traded as commodities like gold or oil. One of life's most essential building blocks is becoming increasingly scarce, so we decided to visit one of the longest-running cloud-seeding operations in the country to learn about how this technology is being used to increase the amount of water yielded by the clouds above our heads.

Cloud seeding has been practiced for decades and has many different techniques and applications. It's used to alleviate fog at airports, reduce the size of hail, and increase rain or snowfall. In a most extreme example, it was weaponized by the US military against the people of Vietnam. After this clandestine operation known as Project Popeye was revealed, environmental modification was internationally banned as a tool of warfare.

The goal of the cloud seeding operation we visited in California's Santa Barbara County was far more benign: to increase rainfall over specific reservoirs.


This type of cloud seeding equipment goes by the name AHOGS (Automated High-Output Ground Seeding System).


Cloud seeding can be done by air using planes or at strategically located sites on the ground, which are able to take advantage of desirable wind and weather patterns to get their seeding agents up into the clouds without the need for a flight.

The seeding agents used in cloud seeding range from dry ice, to liquid propane, to potassium iodide, or in the case of the site we visited: silver iodide. Silver Iodide works as a cloud seeding agent because its molecular structure is similar to ice, making it a suitable point for water molecules to condense around and fall to Earth as rain or snow. Silver and iodine are both present in nature, and a 2013 report from the Utah Department of Health concluded that "silver from cloud seeding projects is not expected to harm people's health."

Garrett Cammans, president of North American Weather Consultants, told us that although he believes cloud seeding to be a sustainable way to generate more water, it isn't a substitute for water conservation, which will be ever more important going into the future.

To see a full walkthrough and demonstration of the cloud seeding equipment and an in-depth explainer of how it works, check out the video of our visit down below.

Watch this: Cloud-seeding site walk-through and demonstration